1. Field of the Invention
The present invention relates to a motor control system and method for wear compensation of an electromechanical brake, and more particularly, to a motor control system and method using electronic pedal (E-pedal) information for wear compensation of an electromechanical brake in a braking process of a vehicle.
2. Discussion of Related Art
Research and development for the replacement of an electromechanical part of a traditional hydraulic component due to depletion possibility of petroleum fuel and environmentally-friendly constraints in the automotive sector are being actively conducted.
As a part thereof, brake-by-wire technology using the electromechanical brake with which the existing hydraulic brake is replaced in the automotive brake sector is emerging as the next generation brake technology.
In addition, the brake-by-wire technology using the electromechanical brake has a faster response characteristic than the existing hydraulic brake and provides a shorter brake distance in the same driving condition. Thus, the brake-by-wire technology using the electromechanical brake is expected to contribute to the improvement of vehicle safety.
In a configuration, the existing hydraulic brake is configured to include a hydraulic booster for boosting a pedal force by utilizing a negative pressure of an engine, an oil pipe, and a hydraulic caliper.
A brake system based on the brake-by-wire technology is configured to include an electronic pedal configured to convert the driver's braking intention into an electrical signal, a wire, and an electromechanical brake.
In the case of the hydraulic brake, an oil seal mounted between a hydraulic piston and a cylinder plays a role in automatically constantly adjusting a gap between a disc and a pad regardless of an amount of pad wear.
On the other hand, because there is no oil seal in the electromechanical brake, a function of adjusting a gap between discs needs to be separately implemented regardless of an amount of pad wear.
When the wear compensation is not achieved, the driver is inconvenienced during driving due to a non-linear response characteristic that a clamping force generation time is felt differently with respect to the same pedaling amount in a viewpoint of the driver. When the amount of pad wear is large, the merit of the faster response characteristic of the electromechanical brake is reduced.
In the case of the existing developed electromechanical brake, motor control according to a position control loop scheme for this wear compensation is performed and it is necessary to measure or estimate an amount of wear for the motor control according to the position control loop.
However, it is necessary to mount an expensive contactless displacement sensor capable of directly measuring an amount of wear or an additional mechanism is required when an amount of wear is measured and there is a disadvantage in that accuracy is degraded when the amount of wear is estimated.